Method and system for reducing body weight in an enclosed atmospheric environment

ABSTRACT

A system and method for passive hypoxic training provides a person with a low oxygen (hypoxic) environment. Oxygen sensors automatically monitor and control oxygen levels to maintain the altitude desired. CO 2  levels are monitored and CO 2  is eliminated so that the air a person breathes is substantially clean and fresh. Exposure to a high altitude environment produces physiological changes in a person&#39;s body, which becomes more efficient at absorbing and transporting oxygen. Using the present method and system, athletes obtain the benefits of sleeping at a simulated altitude in the user&#39;s own home for six to twelve hours, rather than traditional altitude therapies in which athletes spend two to three weeks at high altitude before an athletic competition to obtain similar benefits. This system allows for “live high train low” altitude training that has been shown in controlled studies to provide superior benefits to “live high train high” training.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of prior pending U.S. patentapplication Ser. No. 10/806,886, filed Mar. 22, 2004, entitled “METHODAND SYSTEM FOR REDUCING BODY WEIGHT IN AN ENCLOSED ATMOSPHERICENVIRONMENT”, which is a continuation application of Ser. No.10/423,692, filed Apr. 24, 2003, entitled “METHOD AND SYSTEM FORPROVIDING A DESIRED ATMOSPHERE WITHIN AN ENCLOSURE,” now U.S. Pat. No.6,827,760, which is a continuation application of issued U.S. patentapplication Ser. No. 09/948,410, filed Sep. 6, 2001, entitled “ALTITUDESIMULATION METHOD AND SYSTEM,” now U.S. Pat. No. 6,565,624, which claimspriority from U.S. Provisional Patent Application No. 60/230,946, filedSep. 6, 2000. The entire disclosures of the above-identifiedapplications are considered to be part of the disclosure of the presentapplication and are fully incorporated herein by reference.

FIELD OF THE INVENTION

The present invention is directed to a method and system for reducingthe body weight of a person in an enclosed atmospheric environment, andparticularly, is directed to a method and system in which ambient oxygenand carbon dioxide levels are monitored and adjusted to provide desiredphysiological benefits derived from a person or animal spending time inan altitude environment to enhance weight reduction, improve athleticperformance and/or to relieve altitude sickness symptoms for otherindividuals. High and low oxygen environments affect the physiology indifferent ways providing health and athletic benefits.

BACKGROUND OF THE INVENTION

Going to a higher altitude or reduced oxygen environments is safe whendone properly. Millions of air travelers experience high altitude whenthey fly in aircraft pressurized to 6-8,000 feet. Hundreds of thousandsof tourists visit Colorado's high country and stay at altitudes rangingfrom 8,000 feet (Vail or Aspen, Colo., USA) to 11,000 feet (Leadville,Colo., USA). These same tourists enjoy shorter stays at 12,000 feet (topof Loveland Pass) to 14,000 feet (top of Pikes Peak).

However, medical problems due to high altitude include a number ofuncomfortable symptoms and some potentially dangerous conditions, allresulting from the decrease in the oxygen concentration in the blood.Altitude sickness is not a specific disease but is a term applied to agroup of rather widely varying symptoms caused by altitude. The primarycause is decreased oxygen. People react differently to altitude atdifferent times and different people react differently to altitude.Physical fitness does not confer any protection against acute mountainsickness and does not facilitate acclimatization. Altitude effectsresult from the lower oxygen content of the air—not from the lowerbarometric pressure. At 18,000 feet the amount of oxygen molecules percubic foot of air is approximately one half that of sea level.

Additionally, going too high too fast causes altitude sickness. When aperson is exposed to a higher altitude for longer periods, he/sheacclimatizes to the higher altitude. By acclimatizing slowly, a personcan usually avoid the symptoms of altitude sickness. Symptoms ofaltitude sickness may include: nausea, headaches, sleeplessness,weakness, malaise, difficulty breathing, feeling “hung over”, lethargy,a loss of appetite, altered thinking, and/or feeling “intoxicated”.

During acclimatization there is an increase the body's efficiency inabsorbing, transporting, delivering and utilizing oxygen. The mostimportant processes in acclimatization are:

-   -   (a) An increase in respiratory rate and volume. This change        usually begins at around 3,000 feet and may not reach a constant        value until several days after arrival at high altitude.    -   (b) Changes in the pulmonary circulation. During exposure to any        kind of low oxygen environment, including high altitude, the        pressure in the pulmonary arteries is elevated and the        capillaries of the lung are more fully infused with blood        increasing the capacity of the circulatory bed of the lung to        absorb oxygen.    -   (c) An increase in the number of red blood cells. Shortly after        arrival at high altitude an increase in the number of red blood        cells in the blood occurs. Later red blood cell production by        the bone marrow is increased so that the blood contains more red        cells than at sea level. Since the red cells carry oxygen the        increased number of red cells permits each unit of blood to        carry more oxygen. This process reaches its maximum in about six        weeks.    -   (d) Increased cardiac output. During the first few days at high        altitude, the volume of blood pumped by the heart per minute is        increased, which increases the rate of oxygen delivery to the        tissues.    -   (e) Changes in the tissues of the body. Prolonged exposure to        altitude is accompanied by the changes in the tissues that use        oxygen, particularly muscle, which permit normal function at        very low oxygen pressures.

These changes include an increase in the number of capillaries withinthe tissue, and an increase in the concentration of enzymes, whichextract oxygen from hemoglobin, as well as an increase in the volume ofmitochondria, which are the cellular structures within which theseenzymes are located.

The physiological effects of altitude acclimatization have beendocumented for many years. These effects include:

-   -   (a) An increase in total blood volume    -   (b) An increase in red blood cell mass    -   (c) An increase in VO2 max−the maximum amount of oxygen the body        can convert to work    -   (d) An increase in hematocrit, the ratio of red blood cells to        total blood volume    -   (e) An increase in the lungs ability to exchange gases        efficiently

Together these changes produce an increase in the oxygen carryingcapacity of the blood and the body's ability to use the oxygentransported resulting in a major difference in the body's ability toperform work both at altitude and at sea level. The net result of suchchanges is an improvement in athletic performance.

The time required for the different adaptive processes is variable. Therespiratory and biochemical changes are typically complete in six toeight days. The increase in the number of red blood cells is about 90percent of maximum at three weeks. In general, about 80% of adaptationis completed by 10 days and 95% is completed in six weeks. Longerperiods of acclimatization result in only minor increases in highaltitude performance. However, continued exposure to altitude doesmaintain the physiological acclimatization. After return to sea level,acclimatization starts to be lost after 10-15 days. Red blood cellcounts remain higher for up to 6 weeks.

Living at a high altitude is essential to maximize the oxygen carryingcapacity of the blood and improving athletic performance. In theirlandmark study published in the July 1997 issue of the Journal ofApplied Physiology, Dr Benjamin Levine and Dr. James Strey-Gundersen ofthe University of Texas Southwestern Medical Center demonstratedconvincingly that athletes perform best when living (including sleeping)at high altitude and training at low altitude. Their study of 39 eliterunners showed a marked increase in performance (at sea level as well asat altitude) among the group that lived at high altitude and drove downto low altitude for training. There was no performance improvement inany of the other groups (living high and training high, living lowtraining low, or living low and training high.).

Further studies have also shown that training at low altitude iscritical to getting the best quality training. At high altitude theblood is not fully saturated with oxygen. While the athlete's bloodwould be 97-98% saturated with oxygen at sea level it may be only 80%saturated at 14,000 feet. As a result the athlete at altitude is unableto work or train as hard. U.S. Olympic Team cyclists at their highaltitude training camp found they could work harder by riding cyclingergometers while wearing oxygen masks to simulate sea level. A riderthat could put out 400 watts at altitude could put out 480 watts at sealevel with the same perceived exertion. In short, athletes benefit morefrom their training at sea level than from training at high altitude.This study and others show that the optimal training program includesliving high and training low.

Research shows that the body's production of erythropoietin (the naturalglycoprotein produced by the kidneys that signals the bone marrow tomake more red blood cells) goes up dramatically as altitude increasesfrom 6,000 feet (30% increase over sea level) to 14,500 feet (300%increase over sea level.) Most training regimens simply do not train theathlete at low enough elevations while allowing them to sleep at highenough elevations to gain the maximum benefit from training. In apreferred embodiment, it is recommended that a person sleep at analtitude of 8,000-13,000 feet for the maximum acclimatization effect,after a period of acclimatization at lower altitudes.

What limits exercise at high altitude is the lack of oxygenconcentration. Mountain air contains less oxygen than air at sea level.By reducing the amount of oxygen in the room the equipment simulateshigh altitude.

The amount of exercise that can be performed at high altitude is lessthan at sea level and the heart rate reached during maximal exercise isless. This indicates less cardiac work. Maximal exercise capacitydecreases progressively with higher altitudes. So it would be desirableto sleep high and train low.

The beneficial effect of sleeping high and training low is that theoxygen processing capacity of the body is increased. This allows thebody to do more work (run, swim, ski, or cycle faster) at the same levelof physical exertion and heart rate. The body can also perform the sameamount of work as it did prior to living high and training low at lowerexertion rates and lower heart rates. The athlete can remain in anaerobic state longer and work harder without becoming anaerobic. Theathlete can perform at higher levels while still using fat as a fuelinstead of sugars. This allows for greater performance levels and fastertimes while decreasing lactic acid production.

Research has also shown that athletes who train at low altitude but liveat high altitude perform better in endurance, and running speed, thanathletes who train and live at high altitude or who live and train atlow altitude. “High-low” athletes also recover faster and increase theirVO2 max. Moreover, when people plan to participate in an athletic eventat high altitude it is desirable to train at high altitude before theevent to acclimatize to the conditions. Therefore, there is a need tosimulate both high altitudes and low altitudes.

There have been various attempts at providing systems for simulating adifferent altitude from the altitude that a person resides in order topresumably address the debilitating effects of increased altitude,and/or to obtain some of the advantages of purposely simulatingdifferent altitudes for, e.g., athletic training. Some of these arediscussed immediately below.

Heiki Rusko in Finland introduced nitrogen into an enclosed house usingbottled nitrogen to reduce oxygen levels in an altitude house. Thisapproach suffered from high cost, low convenience and an inability tocontrol CO₂. Only high altitude was simulated, not low altitude.

Nils Ottestad in Norway improved upon this concept by using an oxygenconcentrator, a magnetic gate, a fan, a CO₂ scrubber, oxygen sensors,and CO₂ sensors. In his invention, the oxygen concentrator was runningat all times. A user activated the CO₂ scrubber. Oxygen sensors measuredoxygen levels and sent data to a control panel that only controlled thealarm, the magnetic gate, and a fan. This approach suffered fromrequiring the user to control the CO₂ scrubber and a general lack ofsophistication. The control panel did not control the oxygenconcentrator, the CO₂ scrubber, or the high CO₂ alarm. Fans were notemployed in high CO₂ situations. Only high altitude was simulated, notlow altitude.

Additionally, U.S. Pat. No. 5,964,222 filed Dec. 3, 1997, U.S. Pat. No.5,799,652 filed Jul. 21, 1995, U.S. Pat. No. 5,924,419 filed Feb. 8,1997, and U.S. Pat. No. 5,850,833 filed May 22, 1995, all of which haveKotliar as the inventor, describe the use of an oxygen concentrator tointroduce nitrogen into an environment to thereby provide oxygendepleted air. This approach suffers from a limited ability to controlaltitude and CO₂ levels. Moreover, Kotliar's systems are only capable ofsimulating high, rather than low altitudes.

Accordingly, it would be desirable to have a more cost effective methodand apparatus that could better simulate variable altitudes, and inparticular, easily simulate both lower and higher altitudes than thecurrent altitude of a person.

Definition of Terms

Simulated altitude, or physiological altitude is defined to be thepartial pressure of oxygen that corresponds to a particular actualaltitude. The partial pressure of oxygen is influenced by the oxygenconcentration and the atmospheric pressure.

SUMMARY OF THE INVENTION

The present invention is referred to herein as a “Colorado MountainRoom” (also denoted as CMR herein) and encompasses both a method and asystem for adjusting O₂ and CO₂ levels to provide benefits to, e.g., thereduction of body weight, the training of athletes, the treating orpreventing altitude of sickness as well as other altitude or altitudechange related conditions. For example, high oxygen environments relievesymptoms of altitude sickness and allow for people to sleep more easily.In one embodiment the Colorado Mountain Room controls oxygen levels in aroom, for both allowing the user to simulate high altitudes (low oxygen)for purposes of altitude acclimatization and athletic training, and tosimulate low altitude (high oxygen levels) for athletic training. In oneembodiment, the Colorado Mountain Room requires a reasonably well sealedenvironment (a room or enclosure such as a tent). However, alternativeembodiments that are “leaky” can be provided.

The Colorado Mountain Room may have penetrations through the walls toallow for the passage of hoses, and to allow for the controlled passageof air through a gated penetration. In one embodiment, the presentinvention includes the following components (i.e., the “equipment”):

-   -   (a) A oxygen concentrator—This may be a molecular sieve to        separate oxygen and nitrogen molecules. Such a molecular sieve        removes approximately 5 liters of oxygen from the room per        minute.    -   (b) A CO₂ sensor this measures the amount of CO₂ in the room.        CO₂ is produced by breathing.    -   (c) A CO₂ scrubber—This eliminates CO₂ to keep the air fresh and        clean within the CMR.    -   (d) An oxygen sensor—This measures the amount of oxygen in the        room within the CMR.    -   (e) A temperature sensor—This sensor measures the temperature        within the Colorado Mountain Room.    -   (f) An ambient pressure sensor—This sensor measures the ambient        air pressure in the Colorado Mountain Room.    -   (g) A ventilation fan, a vent, a gate, blower, etc.—This brings        in fresh air into CMR when oxygen levels therein fall below        desired levels, or carbon dioxide levels rise above desired        levels, and if either oxygen or CO₂ are outside of their safe        range.    -   (h) A controller—This controller controls the oxygen        concentrator, a CO₂ scrubber, and the ventilation fan for        altering the percentage of oxygen in the room, removing carbon        dioxide, and bringing in fresh air and monitoring oxygen and        carbon dioxide levels. If either oxygen or carbon dioxide levels        are out of their safe ranges an alarm of the present invention        is triggered and the ventilation fan is turned on to bring fresh        air into the room. The oxygen sensor, the CO₂ sensor, the        temperature sensor, and the ambient pressure sensor are also        connected to the controller. The computerized controller        includes a computer, an analog-to-digital converter module, a        relay output module, a viewing panel, and appropriate power        supplies. The controller's computer: (i) activates and        deactivates the attached above-identified oxygen concentrator,        CO₂ scrubber, and ventilation fan, and (ii) displays information        on a digital control panel (also denoted a visual display panel        herein) using the signals received from the above-identified        sensors.    -   (i) An uninterruptible power source—This power source powers the        sensors, the control panel and the ventilation fan in case of a        power outage.

In one embodiment, the equipment identified above is sized to operatewithin a tightly sealed room of about 1,000 cubic feet. The ability ofthe equipment to create an altitude simulation space is dependent on theroom's air infiltration rate and oxygen removal rate, or nitrogenintroduction rate of the equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constitute a part of this specification and include anexemplary embodiment of the invention, which may be embodied in variousforms. It is to be understood that in some instances various aspects ofthe invention may be shown exaggerated or enlarged to facilitate anunderstanding of the invention.

FIG. 1 illustrates the information to be input in at least oneembodiment of the CMR.

FIG. 2 shows the various components of an embodiment of the presentinvention when installed in a user's bedroom.

FIG. 3 shows an example of these predictions obtained from theprediction model of the present invention when using the initialconditions given in FIG. 1.

FIG. 4 shows an embodiment of the present invention configured tosimulate a low altitude enclosure.

FIG. 5 shows an embodiment of the present invention configured toprovide a higher than normal atmospheric content of CO₂.

FIG. 6 shows an embodiment of the present invention that is portable andconfigured to simulate a higher altitude than the ambient exterioraltitude.

FIG. 7 shows another embodiment of the present invention that isportable and configured to simulate a higher altitude than the ambientexterior altitude and wherein the control thereof is substantiallymanual.

FIG. 8 shows another embodiment of the present invention that isportable and configured to simulate a higher altitude than the ambientexterior altitude, and wherein the enclose is not tightly sealed (i.e.,it is “leaky”).

FIG. 9 shows another embodiment of the present invention that isportable and configured to simulate a higher altitude than the ambientexterior altitude, and wherein the enclose is not tightly sealed andinstead has a substantially constant air infiltration rate. Note that anitrogen filled container may be used to decrease the oxygen content ofthe CMR 50.

FIG. 10 shows another embodiment of the present invention that isportable and configured to simulate a higher altitude than the ambientexterior altitude, and wherein the enclosure is not tightly sealed andinstead has a substantially constant air infiltration rate.

FIG. 11 is a flowchart illustrating the steps for the calibration andcompensation for drift in the oxygen sensors.

FIG. 12 shows one embodiment of an oxygen concentrator for the presentinvention.

FIG. 13 shows a perspective view of three filters that may be providedin an oxygen concentrator for the present invention.

FIG. 14 shows a high level flowchart of the steps performed by thecontroller in determining (in response to a user's input) the altitudesimulation technique (i.e., mode) which the controller is to use incontrolling the CMR.

FIG. 15 shows a high level flowchart of the steps performed by thecontroller when the controller is performing a high altitude (i.e.,higher than the actual altitude) simulation via a reduction in oxygenand an increase in a gas such as nitrogen, helium, or other gas that istypically non-reactive with a user.

FIG. 16 shows a high level flowchart of the steps performed by thecontroller when the controller is performing a low altitude (i.e., lowerthan the actual altitude) simulation via an increase in oxygen withinthe CMR.

FIG. 17 shows a high level flowchart of the steps performed by thecontroller when the controller is performing a high altitude (i.e.,higher than the actual altitude) simulation via a reduction in oxygenand an increase in CO₂.

FIG. 18 shows a high level flowchart of the steps performed by thepredictive computer model of the present invention.

FIG. 19 shows another set of input or initialization data for thepredictive computer model.

FIG. 20 shows a graph of the predicted percentage of oxygen from initialoperation of the enclosure of the CMR 50 when the input data of FIG. 19is input to the predictive computer model.

FIG. 21 shows a graph of the predicted concentration of CO₂ in theenclosure of the CMR 50 when the input data of FIG. 19 is input to thepredictive computer model.

FIG. 22 shows a graph of the predicted simulated altitude in theenclosure of the CMR 50 when the input data of FIG. 19 is input to thepredictive computer model.

FIG. 23 shows a graph of the predicted oxygen consumption by user(s) inthe enclosure of the CMR 50 when the input data of FIG. 19 is input tothe predictive computer model.

FIG. 24 shows a graph of the predicted concentration of CO₂ (in days) inthe enclosure of the CMR 50 when the input data of FIG. 19 is input tothe predictive computer model.

FIG. 25 shows a graph of the predicted simulated altitude (in days) inthe enclosure of the CMR 50 when the input data of FIG. 19 is input tothe predictive computer model.

FIG. 26 shows a graph of the predicted percentage of oxygen (in days) inthe enclosure of the CMR 50 when the input data of FIG. 19 is input tothe predictive computer model.

FIG. 27 shows another graph of the predicted concentration of CO₂ (indays) in the enclosure of the CMR 50 when the input data of FIG. 19 isinput to the predictive computer model.

FIG. 28 shows another graph of the predicted simulated altitude (indays) in the enclosure of the CMR 50 when the input data of FIG. 19 isinput to the predictive computer model.

DETAILED DESCRIPTION

The features of the present invention are set forth above in the Summaryof the Invention and are depicted generally in the embodiments in theaccompanying figures. To supplement the description of the presentinvention and to provide general background relating thereto, Applicantincorporates by reference in their entirety the following issued U.S.patents for further clarification of the present invention: U.S. Pat.No. 5,964,222 entitled “Hypoxic Tent System” filed Dec. 3, 1997; U.S.Pat. No. 5,924,419 entitled “Apparatus for Passive Hypoxic Training andTherapy” filed Feb. 8, 1997; U.S. Pat. No. 5,850,833 entitled “Apparatusfor Hypoxic Training and Therapy” filed May 22, 1995; U.S. Pat. No.5,799,652 entitled “Hypoxic Room System and Equipment for HypoxicTraining and Therapy at Standard Atmospheric Pressure”, filed Jul. 21,1995; and U.S. Pat. No. 5,467,764 entitled “Hypobaric Sleeping Chamber”filed May 13, 1993. It is to be understood, that the present inventionmay be embodied in various forms. Therefore, specific details disclosedherein are not to be interpreted as limiting, but rather as a basis forthe claims and as a representative basis for teaching one skilled in theart to employ the present invention in virtually any appropriatelydetailed system, structure or manner.

At least some of the above-identified components of the presentinvention will now be described in further detail. The essentialfeatures of the present invention are set forth above in the Summary ofthe Invention and are depicted generally in FIGS. 3 10. In oneembodiment, the Colorado Mountain Room 50 includes an enclosed space 54where the altitude or carbon dioxide concentration is controlled.

Computerized Controller 58

The computerized controller 58 allows a user to choose one of thefollowing operational modes: high altitude, low altitude, or high CO₂.Once the operational mode is selected, the computer may require the userto enter the actual altitude of the CMR. Since actual altitude affectshow the desired altitude is simulated, in one embodiment, the user mustenter the actual altitude where the equipment is installed. Note that atsea level (e.g. Los Angeles) a 13.4% oxygen concentration simulates12,500 feet. But at 8,000 feet (e.g. Vail), a 13.4% oxygen concentrationsimulates 19,750 feet. Thus, for embodiments of the invention that use arelative amount of O₂ to simulate a desired altitude, an accuratedetermination of the actual altitude is important. In one embodiment thecontroller utilizes a barometric pressure transducer to measureatmospheric pressure, and thus determine the users “physiological” orsimulated altitude. This reading may be compared to the user's input oftrue elevation above sea level. This feature makes user error lesslikely and serves as a safety feature keeping oxygen levels appropriateto the elevation above sea level. In addition it serves as a mechanismto disallow improper use by the user (i.e. entering false low altitudereadings to increase the upper limit of altitude simulation of thedevice.). Accordingly, the computerized controller 58 compares the userinput altitude of the site with the ‘pressure altitude’ derived from theambient pressure sensor. If the two altitudes are significantlydifferent, the computerized controller 58 requires the user to enter theactual altitude again and warns that the ambient pressure sensor may befaulty.

After comparing the user-entered altitude with the pressure altitude atthe site, the computerized controller 58 adjusts the oxygen sensor tothe known ambient oxygen percentage of 20.94%. The Colorado MountainRoom 50 must be at the ambient oxygen partial pressure (open to theexternal environment) during this procedure. In one embodiment of theinvention, sensors are calibrated to a known oxygen level provided byanother device such as an oxygen analyzer, allowing the user torecalibrate the sensors without opening the Colorado Mountain Room tothe external environment and thus losing the high or low oxygen levelalready attained by the device.

If the present invention is in the high altitude mode or the lowaltitude mode, the computerized controller 58 permits the user to selecta simulated altitude for the Colorado Mountain Room 50 that is,respectively, higher or lower than the actual altitude. In oneembodiment, the simulated altitude can be any value between sea leveland 12,500 feet. The simulated altitude must be above the actualaltitude when the present invention is in high altitude mode or belowthe actual altitude when the present invention is in low altitude mode.

If the CMR 50 is in the High Altitude mode, the computerized controller58 tests to see whether the Simulated Altitude is more than 250 ft abovethe Desired Altitude. If the answer is no, the O₂ concentrator isactivated. If the answer is yes, the computerized controller 58 tests tosee whether the Simulated Altitude is more than 750 ft above the DesiredAltitude. If the answer is no, the Fan Gate is deactivated. If theanswer is yes, the Fan Gate is activated and the computerized controller58 tests to see whether the Simulated Altitude is greater than 16500feet. If the Simulated Altitude is greater than 16500 ft, the Alarm isactivated as a safety feature. The computerized controller 58 continuesto monitor the Simulated Altitude. It activates and deactivates theOxygen Concentrator and the Fan Gate as needed to keep the SimulatedAltitude within 250 ft of the Desired Altitude. In this way, thecomputerized controller 58 maintains the Colorado Mountain Room 50 nearthe simulated altitude.

If the system is in the Low Altitude mode, the computerized controller58 tests to see whether the Simulated Altitude is greater than theDesired Altitude. If the answer is no, the Oxygen Concentrator isdeactivated. If the answer is yes, the Oxygen Concentrator is activatedand the computerized controller 58 tests to see whether the SimulatedAltitude is greater than 16500 feet. If the answer is yes, the Alarm isactivated as a safety feature. The computerized controller continues tomonitor the Simulated Altitude. It activates and deactivates the OxygenConcentrator as needed to keep the Simulated Altitude within 250 ft ofthe Desired Altitude.

If the system is in either the Low Altitude or the High Altitude mode,the computerized controller 58 checks the CO₂ concentration. If the CO₂concentration is greater than 1000 ppm, the computerized controller 58activates the CO₂ scrubber. If the CO₂ concentration is greater than7000 ppm, the computerized controller 58 activates the Fan Gate and theAlarm. The Fan Gate ventilates the CMR 50 to decrease the CO₂concentration. The Alarm warns the user that the CO₂ concentration isout of range. If the CO₂ concentration is less than or equal to 1000ppm, the computerized controller 58 deactivates the CO₂ Scrubber. Thecomputerized controller 58 continues to monitor the CO₂ concentration.It activates and deactivates the CO₂ Scrubber and the Fan Gate to keepthe CO₂ concentration in the CMR 50 below 7000 ppm.

If the system is in any of the three modes, the computerized controllerchecks the Temperature and the Pressure. If the Temperature is not inthe range between 40 F and 104 F, the computerized controller 58activates the Alarm as a warning. If the Pressure is not in the rangebetween 600 mb and 1100 mb, the computerized controller activates theAlarm as a warning.

If the present invention is in the High CO₂ mode, the computerizedcontroller 58 checks to see whether the Simulated Altitude is greaterthan 6,000-9,000 feet. If the answer is yes, the Fan Gate is activatedand the computerized controller 58 checks to see whether the SimulatedAltitude is greater than 12,500 feet. If the answer is yes, thecomputerized controller 58 activates the Alarm as a safety feature. Ifthe Simulated Altitude is below 6,000 ft, the computerized controller 58deactivates the Fan Gate. The computerized controller 58 continues tomonitor the Simulated Altitude to assure that it does not exceed 12,500feet.

When the CMR 50 is closed and occupied by one or more people, the CO₂concentration will rise and the oxygen partial pressure will drop. ThePermissible Exposure Limit (PEL) for CO₂ is 5,000 parts per million(OSHA) over an 8-hour interval. If the system is in the High CO₂ mode,the computerized controller 58 checks to see whether the CO₂concentration is greater than 3250 ppm. If the answer is no, the CO₂Scrubber is deactivated. If the answer is yes, the CO₂ scrubber isactivated and the computerized controller 58 checks to see whether theCO₂ concentration is greater than 5000-10,000 ppm. If the answer is yes,the Computerized Controller activates the Fan Gate and the Alarm. TheComputerized Controller continues to monitor the CO₂ concentration andmaintain it near 3250 ppm for safe and restful sleep.

Note that FIGS. 14 through 17 show the high level steps performed by thecontroller 58 in controlling the simulated altitude of the CMR 50. Inparticular, FIG. 14 shows a high level flowchart of the steps performedby the controller in determining (in response to a user's input) thealtitude simulation technique (i.e., mode) that the controller is to usein controlling the CMR. Additionally, FIG. 15 shows a high levelflowchart of the steps performed by the controller when the controlleris performing a high altitude (i.e., higher than the actual altitude)simulation via a reduction in oxygen and/or an increase in a gas such asnitrogen, helium, or other gas that is typically non-reactive with auser. Additionally, FIG. 16 shows a high level flowchart of the stepsperformed by the controller when the controller is performing a lowaltitude (i.e., lower than the actual altitude) simulation via anincrease in oxygen within the CMR. Finally, FIG. 17 shows a high levelflowchart of the steps performed by the controller when the controlleris performing a high altitude (i.e., higher than the actual altitude)simulation via a reduction in oxygen and an increase in CO₂.

Oxygen Concentrator

The oxygen concentrator is a device that provides a flow of oxygen richair and a separate flow of oxygen depleted air. Oxygen concentrators areavailable commercially (Nidek, Incorporated, Sequal, Incorporated).Oxygen concentrators separate oxygen from ambient air by, e.g., passingthe air through a molecular sieve at high pressure or by a technique ofpressure swing absorption. The oxygen concentrator draws air either fromthe interior of the CMR, or in another embodiment from the exterior ofthe CMR. In the high altitude mode (i.e., low oxygen mode), the oxygenconcentrator removes oxygen from the Colorado Mountain Room 50 oralternatively introduces nitrogen to the Colorado Mountain Room. In thelow altitude (i.e., high oxygen) mode, the oxygen concentrator suppliesoxygen to the Colorado Mountain Room 50 or alternatively removesnitrogen.

As a mechanical safety device, in at least one embodiment, the oxygenconcentrator is equipped with a flow restrictor that prevents thesimulated altitude from rising above 15,000 feet. The size of the flowrestrictor is determined by the size of the Colorado Mountain Room 50,its actual altitude, the flow rate of the oxygen concentrator(s), andthe number of people expected to use it at a time and the airinfiltration rate.

One or more O₂ concentrators are connected to the computerizedcontroller 58. The number and size of oxygen concentrators required foran embodiment of the invention is determined by the size of the ColoradoMountain Room 50, its actual altitude, the air infiltration rate and thenumber of people expected to use it at a time. The computerizedcontroller 58 activates the oxygen concentrator(s), based on the oxygenand carbon dioxide concentrations.

Carbon Dioxide Scrubber

In one embodiment, the CO₂ scrubber is a device that uses a mixture ofCalcium and Sodium Hydroxide (NaOh) pellets to remove CO₂ from the air.When exposed to an acidic gas like CO₂, a strong, exothermic (heatproducing) reaction takes place, which gives off water vapor and bindsthe CO₂ by forming Calcium Carbonate. Water is an important part of thereaction that takes place to bind the CO₂ in that first, the gaseous CO₂reacts with water to form carbonic acid (H₂CO₃). Then, the NaOH reactswith the carbonic acid to produce Na₂CO₂ and H₂O. The Na₂CO₂ reacts withthe Ca(OH)₂ which has been disassociated into Calcium and HydroxideIons. (Ca++ and OH−) to produce CaCO₂ (calcium carbonate, otherwiseknown as limestone.) The CO₂ remains in a stable state. There is a netproduction of three H₂O molecules for every molecule of CO₂ that isremoved.

In one embodiment, the CO₂ scrubber is a commercial air cleaner(DustFree, Inc., Royse City, Tex., USA—Model 250), modified to acceptthe CO₂ scrubbing pellets. The scrubbing pellets are commerciallyavailable (Northwood Designs, Inc., Antwerp, N.Y., USA) in 44-poundkegs. The pellets are scooped into polyester sacks. The polyester sackshold the pellets and trap the dust emitted by them. In one embodiment,the CO₂ scrubber requires four sacks, one on each side of the CO₂scrubber. Ambient air in the CMR is drawn through the sacks by a fan andthen the CO₂ cleansed air is returned to the Colorado Mountain Room 50.The pellets inside the sacks remove CO₂ from the air as it passes overthem.

One or more CO₂ scrubbers are connected to the computerized controller58. The number and size of CO₂ scrubbers required for an application isdetermined by the size of the Colorado Mountain Room 50, the number ofpeople or animals expected to use it at a time and their activity level.The computerized controller 58 activates the scrubber(s), based on thecarbon dioxide concentration as described hereinabove.

Ventilation Mechanism

In one embodiment, the ventilation mechanism includes a vent, fan,blower, gate, or a moveable disc, and a solenoid switch encased in anenclosure. The ventilation fan or other such mechanism is installedthrough the wall of the Colorado Mountain Room 50. The solenoid switchacts to either open or close an air passage into the room. When the airpassage into the CMR is open, the ventilation fan engages to pushambient exterior air into the Colorado Mountain Room 50.

One or more ventilation fans may be connected to the computerizedcontroller 58. The computerized controller 58 activates the ventilationfans, based on the oxygen partial pressure and the CO₂ concentration inthe room. The ventilation fan is a safety device that prevents thealtitude in the room from rising above 15,000 feet and keeps the CO₂concentration below 7,000 parts per million. In one embodiment of theinvention, the oxygen concentrator runs constantly. The computerizedcontroller activates the fan when desired altitude is exceeded. The fanbrings in outside air thus limiting the simulated altitude to thedesired altitude. In addition this embodiment maximizes ventilationthrough the enclosed space.

Oxygen Sensor

In one embodiment, the oxygen sensor detects oxygen in the air by meansof a fuel cell detector that generates an electrical voltageproportional to the oxygen partial pressure. The oxygen sensor consistsof a diffusion barrier, a sensing electrode made of a noble metal suchas gold or platinum, and a working electrode (anode) made of lead orzinc immersed in a basic electrolyte. Oxygen, which diffuses into thesensor, undergoes an electrochemical reaction that converts the oxygeninto lead-oxide (PbO₂). This electrochemical reaction also produces anet electrical voltage.

In one embodiment, the oxygen sensor is commercially available (FigaroUSA, Incorporated Glenview, Ill., USA). The sensor produces a voltage inthe range between 0-50 mv. This corresponds to an oxygen partialpressure between 0 and 1013 mb at sea level.

The present invention improves the accuracy of the oxygen sensor by afactor of 55 (square root of the number of samples) by averagingapproximately 3,000 samples each 30-seconds. The drift of the oxygensensor with changing ambient atmospheric pressure was removed by meansof measuring the ambient atmospheric pressure and compensating for it.In at least some embodiments of the invention, the drift of the oxygensensor with temperature was found to be insignificant in the temperaturerange between 15 C and 27 C.

FIG. 11 shows a flowchart for the calibration, averaging, and pressurecompensation of the oxygen sensor. When the computerized controller isstarted, samples of the oxygen partial pressure (S₀) and the ambientpressure (P) are taken. Next, the percent oxygen is defined to be 20.94%at the initial ambient pressure (P). Then, samples of O₂ and atmosphericpressure within CMR 50 are collected until a total of 3,000 are reached.When 3,000 samples are collected the O₂ is averaged (SAVG), andsubsequently an oxygen concentration for the CMR 50 is determinedaccording to the following formula: 20.94%*(S_(AVG)/S₀)*(P/P_(NXT)).Note that the term P/P_(NXT) is an important aspect of the presentinvention in that this term compensates for CMR 50 ambient pressurevariations to more precisely determine oxygen concentration levelstherein. Additionally, note that for one skilled in the art, numerousother variations in the flowchart of FIG. 11 will become readilyapparent, such as: 1000 samples per minute, 3000 samples in 30 seconds,and 10,000 samples per second.

The oxygen sensor is connected to the computerized controller 58 and theoxygen percentage is displayed on the visual display panel. The oxygenpartial pressure, as derived from the oxygen sensor voltage, is used todetermine the simulated altitude of the Colorado Mountain Room 50regardless of the mode of operation.

CO₂ Sensor

In one embodiment, the CO₂ sensor detects carbon dioxide in the air ofthe CMR by means of an active infrared sensing system that generates avoltage proportional to the concentration of CO₂. The CO₂ sensor isavailable commercially (Telaire, Incorporated, Goleta, Calif., USA—Model8001). The infrared CO₂ sensor includes of an infrared source (emittingbroadband radiation, including the wavelength absorbed by CO₂) and aninfrared detector that are separated by a gas cell. Absorption increaseswith: (a) increasing gas concentration, and (b) increasing optical pathlength between the detector and the source. Knowing the dependence ofabsorption on the CO₂ concentration for a given path length, the sensormeasures the CO₂ concentration, based on the reduction in infrared lightintensity measured by the detector.

Outside ambient concentrations of CO₂ tend to be in the range between370 and 425 parts per million. Heavily industrialized or polluted areasmay have periodic CO₂ concentration peaks that can be as high as 800ppmv in the outside air. The concentration of CO₂ in exhaled breath istypically around 3.8% (38,000 ppmv). Indoor concentrations of CO₂ inoccupied spaces typically range between 500 ppmv and 2,000 ppmv.

Various organizations have established recommended levels for CO₂concentrations in indoor spaces. The American Society of Heating,Refrigeration, and Air Conditioning Engineers (ASHRAE) recommend thatthe indoor CO₂ concentration not exceed 1,000 ppmv. The OccupationalSafety and Health Administration (OSHA) requires that the CO₂concentration not exceed 5,000 ppmv over an 8-hour workday.

The CO₂ sensor of the present invention is connected to the computerizedcontroller 58 and the CO₂ concentration is displayed on the visualdisplay panel. The computerized controller 58 activates the CO₂ scrubberand the ventilation fan to maintain the CO₂ concentration at safe levelsin the Colorado Mountain Room 50.

Temperature Sensor

In at least one embodiment of the present invention, the temperaturesensor detects the temperature of the air by means of a type J or a typeT thermocouple as one skilled in the art will understand. Thethermocouple terminates in a stainless steel ring that is bolted to thehousing of the computerized controller 58. The temperature sensor isavailable commercially (Thermo-Electron, Incorporated, Waltham, Mass.,USA Type J or T). The temperature sensor is operatively connected to thecomputerized controller 58 and the temperature is displayed on thevisual display panel. The computerized controller 58 activates theventilation fan and the audible alarm, if the temperature in theColorado Mountain Room 50 becomes colder than 40 F or warmer than 104 F.This is done to assure that the Colorado Mountain Room 50 is not usedunder conditions where the oxygen partial pressure (simulated altitude)is not accurately measured.

Ambient Pressure Sensor

In at least one embodiment of the invention, the ambient pressure sensordetects the atmospheric pressure by means of a pressure transducer. Itproduces a 0.1-5.1 volt signal over a pressure range of 600-1100 mb. Theambient pressure sensor is available commercially (Setra, Systems, Inc.,Boxborough, Mass., USA—Model 276). The pressure transducer contains twoclosely spaced, parallel, electrically isolated metallic surfaces, oneof which is a diaphragm capable of slight flexing under appliedpressure. The diaphragm is constructed of a low-hysteresis material.These firmly secured surfaces (or plates) are mounted so that a slightmechanical flexing of the assembly, caused by a minute change in appliedpressure, alters the gap between them (creating, in effect, a variablecapacitor). The resulting change in capacitance is detected andconverted to a proportional analog signal.

The ambient pressure sensor is connected to the computerized controller58 and the ambient pressure is displayed on the visual display panel.The computerized controller 58 corrects the oxygen partial pressuremeasured by the oxygen sensor for variations in ambient pressure.Accordingly, it is an aspect of at least some embodiments of the presentinvention to compensate for natural fluctuations in the atmosphericpressure when simulating a desired altitude in the CMR 50. Moreover, thecontroller 58 activates the ventilation fan and the audible alarm, ifthe ambient oxygen partial pressure in the Colorado Mountain Room 50becomes smaller than 600 mb or larger than 1100 mb. This is done toassure that the Colorado Mountain Room 50 is not used under conditionswhere the oxygen partial pressure (simulated altitude) is not accuratelymeasured.

Colorado Mountain Room 50 in Operation.

The user enters the desired altitude (i.e. the desired simulatedaltitude.) This is digitally displayed on the controller 58. A magneticgate seals one or more penetrations into the sealed environment whenpower is supplied to the gate. A solenoid actuator or a small motorholds the gate closed when power is on and opens the gate when power isoff.

One or more fans located within the port are connected to the controller58 in some embodiments. The controller 58 turns the fans off and onbased on oxygen and carbon dioxide levels. One or more O₂ concentratorsare connected to the controller 58. The controller 58 turns the oxygenconcentrators off or on based on oxygen and carbon dioxide levels. Anoxygen concentrator is a device that provides a flow of oxygen rich airand a separate flow of oxygen depleted air. The oxygen concentratordraws air either from the interior of the enclosed space, or in anotherembodiment from the exterior of the enclosed space.

One or more CO₂ scrubbers are connected to the controller 58. Thecontroller 58 turns the scrubber off or on based on oxygen and carbondioxide levels. The controller 58 can also increase flow through the CO₂scrubber by a rheostat or similar device. A CO₂ scrubber is a devicethat uses CO₂ absorbent materials to remove CO₂ from the air.

One or more alarms are connected to the controller 58. The controller 58turns the alarm off or on based on oxygen and carbon dioxide levels. Thecontroller 58 calculates the simulated altitude based on the realaltitude setting and the oxygen level in the room (as reported by theoxygen sensor.) The controller 58 also calculates the oxygen levelrequired to simulate the desired altitude based on the real altitudesetting and the desired altitude input by the user.

In alternative embodiments of the invention, the following compounds mayalso be provided:

-   -   (i) An activated charcoal or carbon filter reduces odors.    -   (ii) Closed loop or split system air conditioning provides        cooling.    -   (iii) A humidifier increases humidity.    -   (iv) A dehumidifier reduces humidity.    -   (v) A HEPA filter or similar device reduces allergens and air        impurities.    -   (vi) Battery back up for oxygen sensor, CO₂ sensor, and fan.

The controller 58 displays: the desired altitude in feet above sea levelor the required oxygen level for the desired altitude; the actual oxygenlevel measured by each sensor as a percentage of air or as a calculationof simulated altitude in feet above sea level; the actual CO₂ levelmeasured by the sensor; and the input altitude provided by a user.

Predictive Computer Model

The Colorado Mountain Room is an enclosed space where the altitude orcarbon dioxide concentration is controlled. A mathematical model wascreated to predict the altitude, the concentration of oxygen, and theconcentration of CO₂ in the room as a function of time. The mathematicalmodel is a mass-balance simulation over time. It requires the followinginformation to establish its initial conditions:

-   -   (1) The length, width, and height of the Colorado Mountain Room.    -   (2) The altitude of the site.    -   (3) The number of people expected to occupy the Colorado        Mountain Room.    -   (4) The oxygen removal or supply rate of the oxygen        concentrator.    -   (5) The number of oxygen concentrators to be used.    -   (6) The per-person heat generation rate. This determines the        activity level in the Colorado Mountain Room. It is converted to        the per-person oxygen consumption rate and carbon dioxide        production rate.    -   (7) The initial oxygen concentration in the Colorado Mountain        Room.    -   (8) The concentration of CO₂ in the ambient atmosphere.    -   (9) The initial CO₂ concentration in the Colorado Mountain Room.    -   (10) The airflow rate through the CO₂ scrubber.    -   (11) The efficiency (%) of the CO₂ scrubber at removing CO₂ from        the air.    -   (12) The air exchange rate in the Colorado Mountain Room.

FIG. 1 shows an example of the data to be input into the predictivecomputer model for initialization. Accordingly, the Colorado MountainRoom Computer Model predicts the CO₂ concentration and the altitude inthe Colorado Mountain Room as a function of time. FIG. 3 shows anexample of these predictions using the initial conditions given inFIG. 1. Using the initialization data of FIG. 1, FIG. 3 shows the CO₂concentration in the Colorado Mountain Room 50 rises to about 3,000 ppmin 12 hours and to 3,850 ppm in 48 hours. As well, the Colorado MountainRoom is predicted to reach a simulated altitude of about 14,000 ft.above sea level in 12 hours and about 15,000 ft. above sea level in 48hours. The Colorado Mountain Room Computer Model is used as follows:

-   -   1. It permits the designer of the Colorado Mountain Room to        specify the appropriate system for each client and site.    -   2. It permits the user of the Colorado Mountain Room to choose        an appropriate size for the enclosed space. Smaller rooms        achieve a simulated altitude more quickly and require a smaller        oxygen removal rate (fewer oxygen concentrators, and less cost).    -   3. By predicting the CO₂ concentration in the Colorado Mountain        Room, the model assures that sufficient CO₂ scrubbing capacity        will be available to keep the room safe and healthy.    -   4. By predicting the highest simulated altitude achieved in the        Colorado Mountain Room, it assures that the room will not become        unsafe for the occupants. And allows the designer to select        appropriate flows for the oxygen concentrator(s).

The Colorado Mountain Room Computer Model computes selected variables,beginning at a time of zero and ending at a time of 7 days. The Modelcomputes each selected variable in time steps until 7 days is reached.The time steps must be short enough to make the simulation accurate andlong enough to make the simulation execute quickly. Our experiencesuggests that the time steps should be less than or equal to 15-minutesin duration.

The CMR Computer Model computes the following variables at each timestep:

-   -   1. The volume of O₂ in the CMR at the beginning of the time        step.    -   2. The volume of O₂ consumed by the occupants of the CMR during        the time step.    -   3. The volume of O₂ removed from the CMR by the Oxygen        Concentrator during the time step.    -   4. The volume of O₂ removed from the CMR by air exchange during        the time step.    -   5. The volume of O₂ added to the CMR by air exchange during the        time step.    -   6. The volume of CO₂ in the CMR at the beginning of the time        step.    -   7. The volume of CO₂ produced by the occupants of the CMR during        the time step.    -   8. The volume of CO₂ removed from the CMR by the CO₂ Scrubber        during the time step.    -   9. The volume of CO₂ removed from the CMR by air exchange during        the time step.    -   10. The volume of CO₂ added to the CMR by air exchange during        the time step.    -   11. The concentration of O₂ inside the CMR at the end of the        time step.    -   12. The Simulated Altitude inside the CMR at the end of the time        step.    -   13. The concentration of CO₂ inside the CMR at the end of the        time step.

High level steps performed by the predictive computer model of the CMR50 are shown in FIG. 18. Additionally, FIG. 19 shows another set ofinput or initialization data for the predictive computer model and FIGS.20 through 28 show graphs of various predicted environmental conditionswithin the enclosure of the CMR 50 as a function of time that the CMR 50is operating/installed.

The following variables and equations are used in the predictivecomputer model of the present invention:

Variables

t=time

delta t=one time interval, 15-minutesO₂ Volume at t (liters)=(Percent O₂ at t−1)/100)*Room Volume(liters)  Equation 1.O₂ Consumption by People at t (liters)=[delta t (min)*People in Room*O₂consumption rate (liters/min)]*[Actual Pressure (mb)/Sea Level Pressure(mb)]  Equation 2.O₂ Concentrator Removal at t (liters)=[delta t (min)*[1013.25/ActualPressure (mb)]*[0.9*[Percent O₂ at t−1/20.94]]*[O₂ Removal Rate perSystem (liters/min)*Number of O₂ Concentrators]*[Percent O₂ att−1/20.94]  Equation 3.O₂ Exchange out of CMR at t (liters)=[delta t (min)]*[Air Change Rate(hr⁻¹)/60]*[Room Volume (liters)*Percent O₂ at t−1/100]  Equation 4.O₂ Exchange into CMR at t (liters)=[delta t (min)]*[Air Change Rate(hr⁻¹)/60]*[Room Volume (liters)*20.94/100]  Equation 5.CO₂ Volume at t (liters)=[CO₂ Concentration at t−1 (ppm)/1,000,000]*RoomVolume (liters)  Equation 6.CO₂ Production from People at t (liters)=[delta t (min)*People inRoom*CO₂ Production rate (liters/min)]*[Actual Pressure (mb)/Sea LevelPressure (mb)]  Equation 7.CO₂ Exchange out of CMR at t (liters)=[delta t (min)]*[Air Change Rate(hr⁻¹)/60]*[Room Volume (liters)*CO₂ Concentration at t−1(ppm)/1,000,000]  Equation 8.CO₂ Exchange into CMR at t (liters)=[delta t (min)]*[Air Change Rate(hr⁻¹)/60]*[Room Volume (liters)*Outdoor CO₂ Concentration(ppm)/1,000,000]  Equation 9.CO₂ Scrubber Removal at t (liters)=[delta t (min)]*CO₂ Scrubber AirflowRate (liters/min)*[CO₂ Scrubber Efficiency (%)/100]*[CO₂ Concentrationat t−1 (ppm)/1,000,000]  Equation 10.Percent O₂ at t=100*[Equation 1−Equation 2−Equation 3−Equation4+Equation 5]/Room Volume (liters)  Equation 11.Simulated Altitude at t(feet)=[3.28084*1000]*[−0.1112+[[−0.1112²]+[4*0.00149]*[6.63268−Ln[[Equation 11*Actual Pressure (mb)/Initial PercentO₂]*[760/1013.25]]]]^(0.5)]/[2*0.00149]  Equation 12.CO₂ Concentration at t (ppm)=[Equation 6+Equation 7−Equation 8+Equation9−Equation 10)*[1,000,000/Room Volume (liters)]  Equation 13.

Further detail of the oxygen concentrator is provided in FIG. 12. Theconcentrator has three ports. One port is an intake air line for airfrom in or out of the simulated altitude space. The second port exhaustsoxygen out of the simulated altitude space. The third port deliversnitrogen into the simulated altitude space.

Plug the concentrator into the carbon dioxide scrubber and connect theoxygen hose to oxygen outlet on the front of the concentrator. Drill ahole in an outside wall and either run the oxygen hose directly outsideor install brass tubing through the wall and attach the hose to thebrass tubing. Seal the hose or tubing on both sides of the wall, insideand outside the room, with caulking.

The O₂ concentrator may be placed in a space adjacent to the altitudesimulation room and as close as possible to the CO₂Scrubber, which is inthe enclosure of the CMR.

When the oxygen concentrator is installed outside the enclosure of theCMR, several holes need to be drilled. One hose will deliver nitrogeninto the room, one hose exhausts oxygen outside, and the last hose willprovide intake air from the room. The intake air hose should be 4 to 6inches above the floor. Both the nitrogen and intake air hoses may beplaced in a wall or door.

Installation Equipment

Connect the intake air hose to the filter hole of the concentratorbehind the door panel. The HEPA filter is inside the hole when it isprovided. Take the HEPA filter out of the concentrator. Place the HEPAfilter on the end of the hose. Seal both sides of the wall around thehose, inside and outside the room, with caulking. Attach the intake airhose to the wall with the filter in an upright position.

As shown in FIG. 12, nitrogen may be delivered into the room through ahose that connects to the brass barb fitting at the bottom left of theconcentrator. The nitrogen hose should be placed in the wall above eyelevel. Seal both sides of the wall around the hose, inside and outsidethe room, with caulking.

The ventilator fan supplies fresh air into the enclosure of the CMR 50and accordingly provides oxygen to the enclosure. In one embodiment,even when the desired simulated altitude is reached, the O₂ concentratorcontinues to operate, decreasing the oxygen concentration in the room,and continuing to raise the simulated altitude. When the simulatedaltitude reaches approximately 100 to 300 feet over the desiredaltitude, the fan turns on bringing in fresh air until the level isapproximately 100 to 300 feet below the desired level. This process forachieving the desired simulated altitude can take over an hour and doesnot affect altitude acclimatization by a user. Moreover, this processprovides the altitude simulation enclosure with a substantial volume offresh air while maintaining the desired oxygen concentration.

The fan can be installed numerous ways. It can be installed on anyinterior wall that has access to an adjacent open space i.e. anotherroom or hallway. It can also be installed on a door.

To mount the fan on the door it is recommended that the fan should bemounted around eye level.

With all the wires attached to the wall seal around the assembly withcaulk. Attach the grill to cover the hole opposite the ventilator fan.

In one embodiment, the oxygen sensor and CO₂ sensor can be mounted tothe wall. The sensors can also be set on a piece of furniture. To mountthe sensors to the wall preferably choose a spot on the wall 4 to 6 feetfrom the bed. Note that in an alternative embodiment, the oxygen sensorand CO₂ sensors may be contained within the control panel. Moreover, ifthe CMR 50 is of sufficient size, more than one oxygen sensor and/or CO₂sensor can be provided therein.

The CO₂ Scrubber needs to be placed in the CMR enclosure within closeproximity of the oxygen concentrator so that they can be operativelyconnected. The O₂ concentrator includes three filters: the intakefilter, the extended life inlet pre-filter, and the HEPA filter as shownin FIG. 13.

Low Altitude Simulation.

A detailed description of this embodiment is provided herein and shownin FIG. 4.

In low altitude mode the oxygen concentrator provides oxygen rich air tothe enclosed environment and vents nitrogen outside the room. Thefollowing conditions and actions are performed by various embodiments ofthe invention.

-   -   (1) Fans—off    -   (2) Gate—closed    -   (3) O₂ concentrator—running    -   (4) CO₂ scrubber—on if CO₂ levels are higher than 500 PPM    -   (5) Alarm—silent    -   (6) Fans—open and blowing for 20 seconds    -   (7) Gate—open    -   (8) O₂ concentrator—running    -   (9) CO₂ scrubber—on if CO₂ levels are higher than 500 PPM    -   (10) Alarm—silent    -   (11) Fans—open and blowing until safe levels are reached    -   (12) Gate—open    -   (13) O₂ concentrator—off until safe levels are reached    -   (14) CO₂ scrubber—on if CO₂ levels are higher than 500 PPM    -   (15) Alarm—sounds    -   (16) Fans—open or closed depending on O₂ levels as above    -   (17) Gate—open or closed depending on O₂ levels as above    -   (18) O₂ concentrator—on or off depending on O₂ levels as above    -   (19) CO₂ scrubber—off    -   (20) Alarm—on or off depending on O₂ levels as above    -   (21) Fans—open or closed depending on O₂ levels as above    -   (22) Gate—open or closed depending on O₂ levels as above    -   (23) O₂ concentrator—on or off depending on O₂ levels as above    -   (24) CO₂ scrubber—on    -   (25) Alarm—on or off depending on O₂ levels as above    -   (26) Fans—open or closed depending on O₂ levels as above    -   (27) Gate—open or closed depending on O₂ levels as above    -   (28) O₂ concentrator—on or off depending on O₂ levels as above    -   (29) CO₂ scrubber—on    -   (30) Alarm—on or off depending on O₂ levels as above    -   (31) Fans—open and running    -   (32) Gate—open    -   (33) O₂ concentrator—on or off depending on O₂ levels as above    -   (34) CO₂ scrubber—on    -   (35) Alarm—sounds    -   (36) Fans—on or off depending on O₂ and CO₂ levels as above        (battery back up)    -   (37) Gate—open (power required to keep closed)    -   (38) O₂ concentrator—failed    -   (39) CO₂ scrubber—failed    -   (40) Alarm—on or off depending on O₂ and CO₂ levels as above        (battery back up is provided for the alarm)

O₂ and CO₂ levels are monitored constantly. The decision whether to turnon the fan occurs every 5 minutes.

There is no need for the CO₂ scrubber to operate when CO₂ levels arenear ambient levels.

Since real altitude effects simulated altitude, the controller 58 mustlimit O₂ to 25% in high oxygen mode (i.e., low altitude simulations).

High CO₂ Simulation.

The Colorado Mountain Room 50 creates a controlled carbon dioxideenvironment, and in particular, can provide a high CO₂ environment.Using the present method and system, individuals derive the benefits ofrestful sleep, using elevated carbon dioxide concentrations as asleep-aid. There are no adverse health effects or side effects known forthis treatment. Many traditional therapies involve the use of chemicalsleep aids with a variety of side effects.

FIG. 5 shows an embodiment of the CMR for high CO₂ simulation.

High concentrations of Carbon Dioxide (>1,000 parts per million) areknown to cause drowsiness without adverse health effects.

The CO₂ sensor in the Control Panel monitors the CO₂ concentration inthe room. When occupied, the CO₂ concentration in the room slowlyincreases. When the concentration exceeds user-selected set point (e.g.,approximately 3,000 to 4,500 ppm, and more preferably approximately 3250ppm), the Control Panel activates the CO₂ scrubber to reduce theconcentration. Should the CO₂ concentration become unhealthy, theControl Panel activates the ventilation fan and sounds a warning alarmuntil the concentration lowers to a healthy one (e.g., approximately5000 to 10,000 ppm).

In this embodiment, the Colorado Mountain Room 50 controller 58 alsomonitors the oxygen partial pressure. Should the oxygen partial pressurein the room decrease to an unhealthy level (e.g. approximately 13,000 to15,000 feet), the Control Panel activates the ventilation fan and soundsa warning alarm until the concentration becomes acceptable again (e.g.,approximately 6,000 to 9,000 feet).

Portable Altitude Simulation.

FIG. 6 shows an embodiment of the CMR that is portable. In someembodiments, it is preferable that the Colorado Mountain Room 50 have anair infiltration rate of less than 0.1 Air Changes per Hour (ACH) to beeffective. However, higher air infiltration rates can be accommodated byincorporating additional oxygen concentrators and/or reducing the sizeof the CMR 50.

The portable CMR embodiment at FIG. 6 encloses the Colorado MountainRoom 50 system in a tent or other portable structure. The tent orportable structure has a fixed volume and a fixed air infiltration rate.The present embodiment functions in the same ways as a stationary CMR.

The present embodiment has the following features:

-   -   1. It is portable. The user can assemble it, use it, disassemble        it, transport it, and store it at will.    -   2. It has a fixed volume regardless of its operating location.        Therefore, the altitude simulation system will be identical for        each time it is used.    -   3. It has a fixed and permanent air infiltration rate.        Therefore, no trained personnel or extra costs are required to        assemble or use the present portable embodiment.    -   4. It can be assembled and used inside an existing room. This        eliminates the need to permanently alter the interior of the        room to provide a CMR. Furthermore, if the existing room is        air-conditioned or cooled by other means, no supplemental        cooling is required inside the embodiment of the invention.

As with other embodiments, the user enters the actual altitude and thedesired altitude using the keypad on the front of the panel. Once thepanel is set, the system starts and the oxygen concentrator is activatedby the panel. The oxygen concentrator runs intermittently under normaloperating conditions. When the oxygen partial pressure reaches thedesired level (desired altitude), the panel turns the concentrator off.Should the oxygen partial pressure decrease significantly below thedesired level (desired altitude), the panel activates the ventilationfan. The ventilation fan provides ambient air from outside theenclosure. This air contains ambient levels of oxygen. It increases theoxygen partial pressure in the enclosure (lowers the altitude) as asafety feature.

When the carbon dioxide level exceeds 1,000 ppm, the scrubber isactivated and runs until the carbon dioxide concentrations falls below1,000 ppm again. If the carbon dioxide concentration exceeds 7,000 ppm,due to increased activity or old absorbent material, the ventilation fanis activated and an alarm sounds.

An alternative portable embodiment of the invention is shown in FIG. 7.This alternative embodiment also provides a tent or other portablestructure as the enclosure. The tent or portable structure has a fixedvolume and a fixed air infiltration rate.

This alternative embodiment has the same features as identified abovefor the initial portable embodiment use thereof. However, whereas theabove initial portable embodiment is controlled by the controller, thepresent alternative portable embodiments has its equipment manuallycontrolled by the user.

Thus, the user adjusts the flow rate of the Oxygen Concentrator tomaintain a simulated altitude according to displays providing the CO₂concentration and the O₂ percentage inside the enclosure provided to theCarbon Dioxide sensor and an Oxygen sensor. Note that the flow rate andthe O₂ percentage necessary to achieve the simulated altitude aredetermined using the Colorado Mountain Room 50 Computer Model previouslydiscussed.

Moreover, the user also manually adjusts the flow rate of the CarbonDioxide Scrubber to control the CO₂ concentration inside the enclosure.If the CO₂ concentration exceeds 7,000 ppm, an alarm sounds.

FIG. 8 shows a third embodiment of the invention that is portable. Thisthird portable embodiment also provides a tent or other portablestructure as the enclosure. The tent or portable structure has a fixedvolume and is breathable (e.g., leaky) instead of substantiallynon-leaky as in the above two embodiments.

This third portable embodiment has the following features:

-   -   1. It is portable. The user can assemble it, use it, disassemble        it, transport it, and store it at will.    -   2. It has a fixed volume.    -   3. It is leaky. Therefore, no trained personnel or extra costs        are required to assemble or use the Colorado Moveable Mountain        Room.    -   4. It can be assembled and used inside an existing room. This        eliminates the need to permanently alter the interior of the        room to create a Colorado Mountain Room 50. Furthermore, if the        existing room is air-conditioned or cooled by other means, no        supplemental cooling is required inside the Colorado Moveable        Mountain Room.

As in the above alternative embodiment, this third embodiment may bemanually controlled by the user. A carbon dioxide sensor and an oxygensensor monitor and display the CO₂ concentration and the O₂ percentageinside the enclosure.

The oxygen concentrator injects Oxygen-depleted (Nitrogen-enriched) airinto the enclosure. The user adjusts the flow rate of the OxygenConcentrator to maintain a simulated altitude. The flow rate and the O₂percentage necessary to achieve the simulated altitude are determinedusing the Colorado Mountain Room 50 Computer Model previously discussed.As in the other embodiments, if the simulated altitude exceeds 15,000feet, an alarm sounds.

Note that in this third portable embodiment, the carbon dioxideconcentration is not elevated because the enclosure is breathable(leaky). The flow rate of the oxygen concentrator is sufficientlypowerful to overcome the leakiness of the enclosure. The CO₂ sensordisplays the CO₂ concentration inside the enclosure. If the CO₂concentration exceeds 7,000 ppm, an alarm sounds.

A fourth portable embodiment of the invention is shown in FIG. 9. Thisfourth embodiment also includes a tent or other portable structure asthe enclosure. The tent or portable structure has a fixed volume and afixed air infiltration rate. The present embodiment has the followingfeatures:

-   -   1. It is portable. The user can assemble it, use it, disassemble        it, transport it, and store it at will.    -   2. It has a fixed volume. Therefore, the altitude simulation        system will be identical for each use.    -   3. It has a fixed and permanent air infiltration rate.        Therefore, no trained personnel or extra costs are required to        assemble or use.    -   4. It can be assembled and used inside an existing room. This        eliminates the need to permanently alter the interior of the        room to create a Colorado Mountain Room 50. Furthermore, if the        existing room is air-conditioned or cooled by other means, no        supplemental cooling is required inside the enclosure.

The present fourth embodiment may be manually controlled by a user orcontrolled by a computerized controller. Note that FIG. 9 shows themanually controlled embodiment in that no controller is shown. A carbondioxide sensor and an oxygen sensor monitor and display the CO₂concentration and the O₂ percentage inside the enclosure.

The controller or the user adjusts the flow rate of the nitrogencylinder (label?) to maintain a simulated altitude. The flow rate andthe O₂ percentage necessary to achieve the simulated altitude aredetermined using the Colorado Mountain Room 50 Computer Model previouslydiscussed. If the altitude exceeds 15,000 feet, an alarm sounds.

The controller or the user also adjusts the flow rate of the CarbonDioxide Scrubber to control the CO₂ concentration inside the enclosure.The CO₂ sensor displays the CO₂ concentration inside the enclosure. Ifthe CO₂ concentration exceeds 7,000 ppm, an alarm sounds.

A fifth portable embodiment of the invention is shown in FIG. 10. Thepresent embodiment includes a tent or other portable structure as itsenclosure. The tent or portable structure has a fixed volume and a fixedair infiltration rate.

The present embodiment has the following features:

-   -   1. It is portable. The user can assemble it, use it, disassemble        it, transport it, and store it at will.    -   2. It has a fixed volume. Therefore, the altitude simulation        system will be identical for each use.    -   3. It has a fixed and permanent air infiltration rate.        Therefore, no trained personnel or extra costs are required to        assemble or use.    -   4. It can be assembled and used inside an existing room. This        eliminates the need to permanently alter the interior of the        room to create a Colorado Mountain Room 50. Furthermore, if the        existing room is air-conditioned or cooled by other means, no        supplemental cooling is required inside the enclosure.        This fifth embodiment may be manually controlled by the user        controlling the infiltration rate of air from outside the CMR        50. For example, it has been discovered by the Applicants that        if the enclosure material has a know air permeability (e.g.,        substantially zero or otherwise), then predetermined closable        vents (as shown in FIG. 10) may be provided in the material,        wherein by opening a certain combination of one or more of the        vents, the CMR 50 will obtain a corresponding predetermined air        infiltration rate (e.g., the air exchange per hour) into the        enclosure. Accordingly, by also knowing the size of the        enclosure, the number of occupants, and their activity levels        within the enclosure, the prediction model for the present        invention (via the prediction model) is able to accurately        predict the O₂ concentration of the enclosure at a maximum        simulated altitude equilibrium state. Accordingly, the present        embodiment of the invention does not require a controller for        controlling the altitude simulation. Thus, a user of the present        embodiment may lookup on a chart, generated from the prediction        model (for his/her particular instance of the CMR 50), to        determine the combination of vents to be open for his/her        current altitude and the desired simulated altitude.

Moreover, note that the present embodiment does not include an oxygenconcentrator. However, a carbon dioxide sensor and an oxygen sensormonitor and display the CO₂ concentration and the O₂ percentage may beprovided inside the enclosure although such devices are not necessary insome embodiments.

The user occupies the enclosure and consumes oxygen. This causes thesimulated altitude inside the enclosure to increase. The desiredaltitude is achieved by adjusting the Infiltration Control Valves. Theair infiltration rate and the O₂ percentage necessary to achieve thesimulated altitude are determined using the Colorado Mountain Room 50Computer Model previously discussed. If the altitude exceeds 15,000feet, an alarm sounds.

The user may manually adjust the flow rate of the carbon dioxidescrubber to control the CO₂ concentration inside the enclosure. The CO₂sensor displays the CO₂ concentration inside the enclosure. If the CO₂concentration exceeds 7,000 ppm, an alarm sounds.

Hybrid Simulation of Altitude.

Because some people find it difficult to sleep at high altitudes or inlow oxygen environments, the Colorado Mountain Room can be configured inan embodiment that incorporates the high CO₂ embodiment with the lowaltitude/high oxygen embodiment thus producing a stimulus to sleep—highCO₂ and removing an obstacle to sleep—high altitude or low oxygen.

Air Exchange Rate in the Colorado Mountain Room 50

In all but the “leaky” third embodiment of the invention, the ColoradoMountain Room 50 preferably must have a low air exchange rate tofunction cost effectively. An air exchange rate of 0.1 air changes perhour or lower is recommended. There are two challenges that must beovercome to achieve the desired air exchange rate. First, one must beable to locate very small leaks in the room in order to seal them.Second, one must determine the actual air exchange rate in the room.

Very small air leaks may prevent the Colorado Mountain Room 50 fromachieving the 0.1 air change per hour air exchange rate that isrecommended. These leaks are found as follows:

-   -   1. Pressurize the Colorado Mountain Room 50 by blowing air into        it using a vacuum with a hose attachment. The hose attachment        must penetrate into the closed room through a temporary hole        that is sealed against leakage. The hole where the ventilation        fan is installed works well for this purpose.    -   2. While the room is pressurized, use a thermal anemometer        (hot-wire anemometer) attached to a sensing wand to search for        small airflows. Any airflow above 0 feet per minute suggests a        leak. Leaks typically occur around door seals, window seals,        wall joints, ceiling joints, floor joints, light penetrations,        and switch penetrations.        The air exchange rate in a home is typically measured using a        large fan and a differential pressure sensor. All the doors and        windows in the home are closed and the fan is installed in one        of the doors. The fan blows a large amount of air into the home,        pressurizing it. When the fan is stopped, a stopwatch and the        differential pressure sensor are used to determine how long the        home remains pressurized. The air exchange rate can then be        computed. This method works for air exchange rates as small as        0.5 air changes per hour. The air exchange rate in the Colorado        Mountain Room 50 may be as small as 0.01 air changes per hour        and must be less than 0.1 air changes per hour. The present        invention includes a CO₂ leakage method and system for        determining the air exchange rate in an embodiment of the        Colorado Mountain Room 50.

The CO₂ leakage method and system performs the following steps todetermine the air exchange rate in the Colorado Mountain Room 50:

-   -   1. Seal the Colorado Mountain Room 50.    -   2. Close the entrance to the Colorado Mountain Room 50.    -   3. Raise the CO₂ concentration in the Colorado Mountain Room 50        to about 5,000 ppm. This may be done by either vigorously        exercising in the room or by releasing CO₂ into the room from a        gas cylinder.    -   4. Terminate the release of CO₂ in the room.    -   5. Note the peak CO₂ concentration achieved and the time of        occurrence.    -   6. Wait for several hours. The longer one waits, the more        accurate the method becomes.    -   7. Note the CO₂ concentration and the time of occurrence again.    -   8. Set the appropriate initial conditions in the Colorado        Mountain Room 50 Computer Model.    -   9. Obtain a prediction of the CO₂ concentration in the Colorado        Mountain Room 50 at the time noted in Step 7.    -   10. If the predicted CO₂ concentration is lower than the        concentration observed in Step 7, reduce the air change rate in        the Computer Model. [Need to clearly describe this model,        probably in detail.]    -   11. If the predicted CO₂ concentration is higher than the        concentration observed in Step 7, increase the air change rate        in the Computer Model.    -   12. Repeat Steps 9-11 until the predicted CO₂ concentration        matches the observed one.

Once the air exchange rate is determined and is less than 0.1 airchanges per hour, the Colorado Mountain Room 50 can be used to simulateeither high and/or low altitudes. The Colorado Mountain Room 50 ComputerModel should accurately predict the time necessary to achieve thesimulated altitude, using the air exchange rate determined in Steps 1-12immediately above.

When a user of the invention enters the actual altitude and the desiredaltitude using the keypad on the front of the input and display panel,the CMR 50 starts and the oxygen concentrator is turned on by thecontroller (if used). The oxygen concentrator runs continuously undernormal operating conditions in at least some embodiments. When oxygenlevels reach the desired level in the enclosure, the controller turns onthe fan to provide external air to the enclosure. This intake air has adifferent oxygen concentration than the air in the enclosure. The fan isturned on and off to maintain the desired oxygen concentration. When thecarbon dioxide level reaches 1,000 PPM the scrubber is turned on low andruns until the carbon dioxide level is reduced to about 750 PPM. Ifcarbon dioxide levels continue to rise, due to increased activity or oldabsorbent material, the scrubber speed is increased to medium at 3,000PPM and high speed at 5,000 PPM. Scrubber speed is reduced as the carbondioxide level is reduced.

Starting the CRM is simple. On the control panel there is a digitalreadout and a set of buttons to use to enter actual altitude and desiredaltitude.

-   -   (a) When the control panel is plugged in the starting screen        will come up with “Colorado Altitude Training” displayed.    -   (b) Select high altitude mode for decreased oxygen. (An        alternative low altitude mode can also be used if the equipment        is used correctly).    -   (c) Within a few seconds a screen asking for the Actual Altitude        of the user will display.    -   (d) Using the + button to go up in 100 ft increments and −        button to go down in 100 ft increments set the altitude that you        live at and then push the Set button.    -   (e) The following screen shows the user what the Actual Altitude        has been set to.    -   (f) If this actual altitude is correct press the Next button. If        not press the reset button    -   (g) The following screen asks the user to enter the Desired        Altitude.    -   (h) Using the + and − buttons the can set the altitude desired        and then pushes the Set button.    -   (i) The display will show the Desired Altitude.    -   (j) If the desired altitude is correct the user presses the        “Next” button. The CRM 50 will then start operating. However, if        the altitude shown is not the desired altitude then press the        reset button    -   (k) To reprogram the system for a new altitude press the reset        button and begin the process over.    -   (l) The final screen shows the current simulated altitude (the        altitude being simulated at the moment) and the current oxygen        concentration in the room. It also shows the desired altitude        that was selected. CO₂ levels are also shown.    -   (m) The simulated altitude reading displayed immediately after        starting the CMR 50 should read within 500 feet plus or minus        the actual altitude.

This is important to establish the accuracy of the oxygen sensor, andthe resulting simulated altitudes. If the display reading is off morethan 500 feet recalibration and/or sensor malfunction may be necessary.

The response to altitude varies tremendously from person to person. Whatmay be too high for one person may be easily tolerated by another. Evenan individual's response may vary from time to time. What cannot betolerated today may be tolerated at a later date. To reduce thelikelihood of altitude sickness when using the present invention tosimulate a higher altitude, a user should start off using the followingprotocol and monitor you're his/her reaction to simulated altitudeincreases. If there are any of the symptoms of altitude sickness, a usershould preferably discontinue use of the present invention forapproximately 24 hours and back off to a lower altitude setting (higheroxygen setting) in the next use of the equipment thereby giving moretime to acclimatize. A good rule of thumb is to allow at least one dayof acclimatization for every 1,000 feet of elevation gain above 7,000feet.

Studies show that 6-12 hours exposure to altitude per day is sufficientto produce the acclimatization effect in the COLORADO MOUNTAIN ROOM 50.However, there is no harm in extending that time per day. The presentinvention may be used any time of day for any activity such as reading,watching TV, talking on the telephone, lap top computer work etc.

The following protocols are suggested for using the present invention tosimulate a higher altitude.

For users at a location less than 5,000 feet above sea level:

-   -   Phase 1—Spend 3-5 days at approximately 7,000 feet. Do not        exceed 9,000.    -   Phase 2—Spend at least 4-5 days at approximately 9,500 feet. Do        not exceed 11,500 feet.    -   Phase 3—Spend at least 5-7 days at approximately 12,000 feet. Do        not exceed 13,500 feet.    -   Phase 4—Sleep at 14,000-15,000 feet from then on. But the user        should have had at least 12 consecutive days of acclimatization        where he/she is exposed to altitude at least 6-8 hours per day.        Do not exceed 15,000 feet at any time.

Note that the simulated altitude may be increased with the control panelin increments as small as 100 feet.

After a 2-3 day interruption go back one phase (e.g., after four days atphase 3 and then three days at sea level; go back to phase 2 for furtheruse of the CMR 50.) After a 4-7 day interruption go back two phases(e.g., after 5 days at phase 4 you spend 7 days at sea level; go back tophase 2). After an interruption of more than 7 days or more go back tophase 1.

For users at a location that is between 5,000 and 7,000 feet above sealevel:

Phase 1—Spend 3-5 days at approximately 9,000 feet. Do not exceed11,000.

Phase 2—Spend at least 4-5 days at approximately 11,500 feet. Do notexceed 12,500 feet.

Phase 3—Spend at least 5-7 days at approximately 13,000 feet. Do notexceed 14,000 feet.

Phase 4—Sleep at 14,000-15,000 feet from then on. But the user shouldhave had at least 12 consecutive days of acclimatization where he/she isexposed to altitude at least 6-8 hours per day. Do not exceed 15,000feet at any time.

After a 2-3 day interruption go back one phase (e.g., if after four daysat phase 3 and then three days at sea level; go back to phase 2.). Aftera 4-7 day interruption go back two phases (e.g., if after 5 days atphase 4 7 days are spent at sea level; go back to phase 2). After aninterruption of more than 7 days or more go back to phase 1.

There are definite limits to how high an individual should go. There areno permanent human habitations above 17,500 feet. Among mountainclimbers the altitudes above 18,000 feet are known as the deteriorationzone and altitudes above 26,000 feet are called the death zone. Abovethis later altitude, there is simply inadequate oxygen for a normalhealthy life. While humans can survive above 18,000 feet for a shorttime, fitness will definitely decrease above this elevation whateverelse you may do. Accordingly, it is an aspect of the present inventionthat a user is alerted and/or one or more fans are activated when thesimulated altitude rises above 15,000 feet.

In some embodiments, the Colorado Mountain Room 50 control panel isequipped with an alarm that sounds when the oxygen or carbon dioxidelevels are outside their desired ranges. The alarm signals the user thatthe CMR 50 needs to be turned off and/or is malfunctioning.

In one embodiment the alarm is triggered at a simulated altitude of16,500 feet. Additionally, the oxygen concentrator is turned off and theair intake fan is turned on. The fan will turn off at 14,800 feet.

In some embodiments of the invention, the alarm is triggered at CO₂concentration of approximately 9,500 ppm. Additionally, the scrubber isset to high speed and the air intake fan is activated.

High carbon dioxide levels indicate either the absorbent material needsto be replaced or the scrubber is not running. If the scrubber isrunning and the carbon dioxide level does not drop change the absorbentand restart the CMR 50.

It is preferred that the present invention be used in conjunction withperiodic tests of hematocrit or hemoglobin. Also recommended is themonitoring of O₂ saturation in the blood, and nucleated redcells/reticulocyte counts.

Since a Colorado Mountain Room 50 works by reducing the oxygen contentof the air, it is important for implementing a substantially air tightstationary embodiment of the invention to select a room that can be madeas air tight as possible. One preferred installation is an enclosure of1,000 cubic feet with no more than two occupants; however, larger roomswith a larger number of occupants can be provided, e.g., for rooms of30,000 cubic feet. The room should be sealed with paint and air sealingtechniques as one skilled in the art will understand.

In one embodiment, the maximum size for a Colorado Mountain Room 50 isabout 10 feet by 12 feet 6 inches with an 8-foot ceiling height or about1,000 cubic feet. Of course, larger rooms can be accommodated withadditional oxygen concentrators. Rooms with no exterior walls are easierto seal, control humidity levels, and provide with cooling and heatingif necessary. Rooms and outside walls are affected by temperature andhumidity differences between inside and outside the space and windspeeds, which affect the infiltration rates of the conditioned space. Asthe number of doors and windows increase the number of pathways for airinfiltration increases. The number of penetrations for electricaloutlets, lights, and plumbing fixtures also increases the number ofpathways for air infiltration. Open floor plans that include largeclosets and or bathrooms increase the size of the room and the equipmentrequirements, and increase the difficulty of sealing the conditionedspace.

The Colorado Mountain Room 50 works by reducing oxygen content in theair. To be effective you need a reasonably air tight room to avoidoutside air from entering the room. Macklanburg Duncan (MD) manufacturesweather stripping and sealing products that can be used to seal roomseffectively. Their website address is www.mdteam.com and is a veryinformative site. MD produces a wide variety of products that areavailable at most home centers, hardware stores, and lumber companies.

Newer buildings tend to be constructed using materials and methods thatreduce air infiltration to minimize heating and cooling needs. Buildingsbuilt before the 1970's may be more difficult to seal effectively due tothe different construction materials and methods used at the time thebuilding was built. Most air leaks in rooms are from the followingbuilding components. Recommendations are included for each component.

-   -   1. Doors—A good quality door that closes easily and tightly is        all that is necessary. A special door is not required. Use an        adjustable door jam kit (weather-stripping, we recommend MD Flat        Profile Door Jamb Weather-strip) to make the door as leak proof        as possible. Install a wooden threshold and a “door sweep” or        “bottom” (weather stripping that attaches to the bottom of the        door, we recommend MD L-Shaped Door Bottom) to provide a seal at        the bottom of the door. Single doors are easier to seal than        double doors. Older French doors are difficult to seal        effectively. Hinged doors are easier to seal than sliding doors.    -   2. Windows—Make sure the windows are shut tightly. No special        windows are required, however the windows need to seal        effectively, which may require installing new weather stripping        to reduce air exchange from the outside. Older windows can be        more difficult to seal, and older double hung windows are        particularly difficult to seal. Windows need to be sealed        between the window frame and the wall framing. The window trim        should be caulked on the inside and outside of the room. On the        inside of the room, caulk the edge of the trim where it meets        the drywall and where it meets the window jamb. On the outside        of the house caulk the edges of the window trim where it meets        the siding and where it meets the window jamb. MD manufactures a        product Shrink & Seal Indoor Kit for windows that will be        difficult to seal. The product is a clear plastic film that        tapes to the wall or trim around the window and completely seals        the window.    -   3. Plumbing—Where pipes enter or exit the room (under sinks,        behind toilets, in showers, and tubs) use caulk or plumbers        putty to seal the area around the pipes. Modern plumbing codes        require traps in drains. Consequently, drains are generally not        a problem. Showers, tubs and sinks can be used normally without        losing altitude. No special plumbing fixtures are required.    -   4. Ducts and Vents—These need to be blocked completely. Close        the registers and seal the duct or vent opening using duct tape        (available at any hardware store, K-mart, Target, etc.). It will        look better and be more effective to remove the register or        grille, seal the duct or vent several inches below the opening        and then replace the register or grille in the opening. If the        vent is large, you can tape a heavy-duty vinyl or urethane        plastic sheet to the duct or vent. Seal off cold air returns and        ventilation fans in the same way. When fan ducts are closed off,        be sure to remove the electrical power to the fan so it is not        turned on. A fan blowing against a closed duct could cause the        fan to overheat.    -   5. Electrical Outlets, Phone Jacks, Cable Jacks and Light        Fixtures—Block unused electrical outlets with outlet plugs or        covers, which are available at any hardware store. Seal the        edges of switch, jack, outlet and light boxes with caulk where        the box meets the drywall. Place foam seals under switch and        outlet cover plates.    -   6. Walls and Ceilings—The materials used in the construction of        the room impact the infiltration rate of the room. Drywall on        the walls and ceiling is ideal. Repair any cracks with spackling        compound, or caulk. We recommend that the walls and ceiling be        painted with one coat of a high quality latex primer sealer, and        two coats of a high quality latex paint. Paint requirements for        walls that may be difficult to seal are listed under the Trouble        shooting section.    -   7. Floor—Most modern flooring is sufficiently airtight. However,        if there are obvious cracks in wooden flooring these should be        filled or repaired to reduce outside airflow. Urethane coating        of a leaky wooden floor may be sufficient to solve the problem.        Even the worst floor can be made airtight with a heavy-duty        plastic sheet placed over the floor, and sealed at the edges of        the room with tape. You may then cover the plastic with ordinary        carpeting or an appropriate sub floor and the flooring material        of your choice.    -   8. Testing for Leakage—Once the Mountain Room equipment is        installed turn it on and monitor the control panel display for        the percentage of oxygen in the room. In a well-sealed room the        percentage of oxygen will decrease to desired levels over a        period of 8-10 hours (longer in large rooms).    -   9. Heat—Ordinary baseboard heating, available for about $75, or        space heaters available for even less are sufficient to heat        most rooms. No special heating is required.    -   10. Air Conditioning—Air conditioning is recommended to cool and        dehumidify the air in the room. Split system air conditioners        are required and are available through Carrier, General Electric        and several other manufacturers. Split systems consist of two        components, an indoor unit placed in the room to be cooled and        an outdoor unit that houses the compressor and exhausts heat.        These systems provide more cooling capacity, are easier to seal        and are architecturally more attractive than window air        conditioners. An air conditioner that does not bring in outside        air, or exhaust indoor air is necessary to avoid interfering        with the lowering of the oxygen concentration in the room.        Window air conditioners often bring in outside air, which        precludes their use in altitude simulation rooms. Single unit        portable air conditioning systems will not work in an altitude        room because they exhaust indoor air. Contact a local mechanical        contractor for more information on split system air conditioners        available in your area. The local contractor provides design and        installation services and can assist you in choosing a system        that cools and dehumidifies the room. Be sure to inform the        contractor that the Mountain Room equipment produces heat so        they can calculate the cooling load of the room including the        heat generated by the concentrator and the scrubber (400 watts        for the concentrator and 200 watts for the scrubber). Be certain        that the air conditioner is sealed effectively when it is        installed.    -   11. Humidifiers and Dehumidifiers—If air conditioning is not        used a dehumidifier is recommended. Ordinary off the shelf units        are fine. In some cases, a humidifier may be desired to increase        humidity in rooms that are air-conditioned. Again, ordinary off        the shelf units are fine.

Move the oxygen sensor around the room to locate areas in the room wherethe oxygen content is higher than the ambient level in the room. Findthe point of entry and seal it. Doors, windows and electricalpenetrations should be checked carefully. Continue locating and sealingleaks until the room remains at the desired oxygen concentration.

When oxygen levels at the wall are higher than the rest of the room andall penetrations are sealed use the following paint recommendations.Paint the walls, if you have not all ready done so, with one coat of ahigh quality latex primer sealer, and two coats of a high quality latexpaint. If the walls are more air permeable than drywall in goodcondition the following paints or similar products are recommended. 1coat Sherwin-Williams Preprite 200 Latex Primer (B28W200.) 2 CoatsSherwin-Williams Epolon II Multi-Mil Epoxy paint (B62-800 series.) Ifthe walls are concrete, the following is recommended. 1 coatSherwin-Williams Heavy Duty Block Filler (B42W46.) 2 coatsSherwin-Williams Epolon II Multi-Mil Epoxy (B62.) Any of the Epoxiescome in any color you choose. Exposed wood ceilings and wood panelingwithout finished drywall underneath may be very difficult to sealeffectively. An additional oxygen concentrator can be used to overpowerthe leaks in the room.

The Colorado Mountain Room 50 equipment can be placed in many differentconfigurations. Placing the oxygen concentrator, control panel, andintake air assembly in the closet of the altitude simulation spaceprovides an installation that maximizes useable floor space andminimizes the visual impact of the equipment.

Sensors should be placed close to the occupants in the enclosure but notso close that artificially high carbon dioxide readings occur. It isrecommended that the sensors be placed about four to six feet away fromthe occupants. Sensors should be placed to monitor air from the room atlarge and not from inside the closet or behind furniture or drapes.

The carbon dioxide scrubber needs to be in the altitude simulation spaceand for best performance needs three feet of unobstructed air spacearound the outlet at the bottom of the scrubber. The scrubber can beplaced in the closet next to or above the concentrator if there isenough air space around the scrubber. The scrubber weighs aboutforty-five pounds when the canister is full of absorbent material. Thescrubber should be placed so it is easy to remove the canister foremptying and refilling. Try removing the empty canister from thescrubber at the desired location before filling the canister. It is mucheasier to remove the canister from the scrubber than to unplug andremove the entire scrubber every time the canister is refilled. Placethe scrubber up off the floor to prevent water from contacting the baseof the unit. Standing water around the base of the scrubber couldcontact electrical components in the base of the unit. If placed onlight colored carpet place the scrubber on a small mat or rug to avoiddiscoloring the carpet.

The intake fan is the control mechanism for the invention in manyembodiments. The fan has to be installed correctly and in good workingorder for the system to operate safely. The intake air fan should beinstalled about eye level, and should be placed as inconspicuously aspossible. The fan needs to be positioned so it will not be obstructed orcovered by furniture or items on closet shelves. The closet is a verygood choice for locating the fan provided the closet wall adjoins aninside space that allows good airflow. Placing the fan in a closet willprobably require leaving the closet door open even if the closet door islouvered. The fan requires a four-inch hole drilled through the walls ofadjoining rooms.

Because the oxygen concentrator creates some heat, in one embodiment theoxygen concentrator is placed in an air-conditioned room. Theconcentrator of the present invention only requires plugging it into thescrubber, installing one hose to an outdoor space and turning it on.

In one embodiment the present invention can also include a carbonmonoxide detector for detecting carbon monoxide in the enclosure. UsesFor The Colorado Mountain Room 50:

The Colorado Mountain Room 50 may be used for providing the followingconditions:

-   -   (a) High Altitude and Diabetes. The Colorado Mountain Room 50        system creates a low oxygen (hypoxic) or high oxygen (hyperoxic)        environment. An oxygen sensor and a computerized controller 58        automatically monitor and control the oxygen partial pressure to        maintain the desired altitude. Carbon Dioxide concentrations are        automatically monitored and controlled by a CO₂ sensor, a        computerized controller 58, a CO₂ scrubber, and a ventilation        fan. Studies with animals suffering from Type-II Diabetes        suggest that exposure to a high altitude environment produces        metabolic changes that lead to a remission or cure of the        disease. Although not bound by theory, the inventors believe        that using the present method and system may lead to a remission        or cure of Type-II Diabetes. The traditional therapies for        Type-II Diabetes involve regular monitoring of blood glucose        levels and the injection or ingestion of insulin. There is        presently no cure for Type-II Diabetes.    -   (b) High Altitude and Coronary Heart Disease. The Colorado        Mountain Room 50 system creates a low oxygen (hypoxic) or high        oxygen (hyperoxic) environment. An oxygen sensor and a        computerized controller 58 automatically monitor and control the        oxygen partial pressure to maintain the desired altitude. Carbon        Dioxide concentrations are automatically monitored and        controlled by a CO₂ sensor, a computerized controller 58, a CO₂        scrubber, and a ventilation fan. Although not bound by theory,        use of the present method and system may slow the progress of        coronary heart disease or aid in the rehabilitation of those        that suffer from it. The traditional preventative therapies for        coronary heart disease include changes to the diet, increased        exercise, and the cessation of risky behaviors (e.g. smoking and        alcohol consumption). The traditional treatments for coronary        heart disease include prescription medications and surgery.    -   (c) High Altitude and Stroke. The Colorado Mountain Room 50        system creates a low oxygen (hypoxic) or high oxygen (hyperoxic)        environment. An oxygen sensor and a computerized controller 58        automatically monitor and control the oxygen partial pressure to        maintain the desired altitude. Carbon Dioxide concentrations are        automatically monitored and controlled by a CO₂ sensor, a        computerized controller 58, a CO₂ scrubber, and a ventilation        fan. Although not bound by theory, use of the present method and        system may lessen the likelihood of stroke or aid in the        rehabilitation of those that suffer a stroke. The traditional        preventative therapies for stroke include changes to the diet,        increased exercise, prescription medications, and the cessation        of risky behaviors (e.g. smoking and alcohol consumption). The        traditional treatments for stroke include prescription        medications and surgery.    -   (d) High Altitude and Obesity. The Colorado Mountain Room 50        system creates a low oxygen (hypoxic) or high oxygen (hyperoxic)        environment. An oxygen sensor and a computerized controller 58        automatically monitor and control the oxygen partial pressure to        maintain the desired altitude. Carbon Dioxide concentrations are        automatically monitored and controlled by a CO₂ sensor, a        computerized controller 58, a CO₂ scrubber, and a ventilation        fan. Although not bound by theory, use of the present method and        system may act to control obesity. Prolonged exposure to high        altitude is known to reduce the appetite and to produce changes        in metabolism that may lead to weight loss. The traditional        therapies for obesity include reducing the intake of calories,        increasing exercise, prescription medications, and surgery.    -   (e) High Altitude and Cancer. The Colorado Mountain Room 50        system creates a low oxygen (hypoxic) or high oxygen (hyperoxic)        environment. An oxygen sensor and a computerized controller 58        automatically monitor and control the oxygen partial pressure to        maintain the desired altitude. Carbon Dioxide concentrations are        automatically monitored and controlled by a CO₂ sensor, a        computerized controller 58, a CO₂ scrubber, and a ventilation        fan. Although not bound by theory, use of the present method and        system may slow the progress of some types of cancer or aid in        the rehabilitation of those that suffer from them. The        traditional preventative therapies for cancer include changes to        the diet, and the cessation of risky behaviors (e.g. smoking,        sun exposure, and alcohol consumption). The traditional        treatments for cancer include prescription medications,        naturopathic remedies, surgery, radiation therapy, and chemical        therapy.    -   (f) High Altitude and Smoking Cessation. The Colorado Mountain        Room 50 system creates a low oxygen (hypoxic) or high oxygen        (hyperoxic) environment. An oxygen sensor and a computerized        controller 58 automatically monitor and control the oxygen        partial pressure to maintain the desired altitude. Carbon        Dioxide concentrations are automatically monitored and        controlled by a CO₂ sensor, a computerized controller 58, a CO₂        scrubber, and a ventilation fan. Although not bound by theory,        use of the present method and system may allow smokers to        overcome their habit more easily. The traditional therapies for        smoking cessation include willpower, medications, acupuncture,        and hypnosis.

While various embodiments of the present invention have been describedin detail, it will be apparent that further modifications andadaptations of the invention will occur to those skilled in the art. Itis to be expressly understood that such modifications and adaptationsare within the spirit and scope of the present invention.

1. A method for providing a desired enclosed atmospheric environmentwithin an enclosure for changing a physical characteristic of a user whoperiodically resides in the enclosed atmospheric environment andbreathes the same, comprising: first obtaining predictive dataindicative of a future composition of constituent gases of said enclosedatmospheric environment, said predictive data being dependent upon atleast two of (a) through (c) following: (a) data indicative of anexpected gas exchange rate between said enclosed atmospheric environmentand an atmospheric environment external to said enclosure, wherein saidenclosure is expected to have a first predetermined state related to agas permeability therethrough; (b) data indicative of an approximatevolume of said enclosure; and (c) data indicative of an expected rate atwhich one or more devices, operably associated with said enclosure forchanging said enclosed atmospheric environment, changes a relativeamount of at least one of the gases of said enclosed atmosphericenvironment, said one or more devices including one or more of: anoxygen concentrator, a CO₂ scrubber and a nitrogen generator; saidpredictive data selected from the group consisting of: (a) dataindicative of an oxygen volume in said enclosed environment; (b) dataindicative of an oxygen consumption by one or more users in saidenclosed environment; (c) data indicative of a rate of oxygen removal;(d) data indicative of an amount of air exiting said enclosedenvironment through said enclosure; (e) data indicative of an amount ofair entering said enclosed environment through said enclosure; (f) dataindicative of a volume of CO₂ in said enclosed environment; (g) dataindicative of a volume of CO₂ being produced by one or more users; (h)data indicative of a CO₂ production from one or more users of saidenclosed environment; (i) data indicative of a CO₂ portion of said airexchange rate exiting said enclosed environment; (j) data indicative ofa CO₂ portion of said air exchange rate entering said enclosedenvironment; (k) data indicative of an amount of CO₂ removed from saidenclosed environment by said CO₂ scrubber; (l) data indicative of arelative amount of oxygen in said enclosed environment; (m) dataindicative of a simulated altitude in said enclosed environment; and (n)data indicative of a concentration of CO₂ in said enclosed environment;using said predictive data to provide an interior of said enclosure witha desired simulated altitude; providing control information forcontrolling a composition of constituent gases of said enclosedatmospheric environment for simulating said desired simulated altitudewhich is different from that of the atmospheric environment external tosaid enclosure; wherein said control information is used for changing acomposition of said constituent gases of said enclosed atmosphericenvironment.